Have any of you tried installing a rear main seal on one of these engines while it's still in the truck and bolted to the transmission? This is important to know because someone who has dropped the the crank in order to buy some room is working in an entirely different world than I. I have all the main caps and the alternator belt loose. I even knocked on the front pulley assembly to get the crank to fall. The seal is way too big to be put in without dropping the crank (it's the right seal). It can not be done. That thing refuses to slide more than a third of the way around the crank, and the only reason it went that far is because the rubber on the outside of the seal got pealed off.
I have gotten the old seal out and driven a screwdriver all the way through the seal hole and around the crankshaft. I even grabbed onto the seal with a pair of needle nosed pliers and tried pushing it. it won't move.
please give me some advice
thanks
brad

 

You should be able to lube it up and slide it in there, as long as you have it turned right. Im sure some more people will chime in here, with alot more help.

 

Yes. I did it to my '73 F100 2wd 390 a few years ago. I jacked up the motor, dropped the pan, and swapped the seal. I loosened all the main bolts but only a turn or two (didn't drop crank), then pulled the rear cap off and slid the old seal out and new one in. I lubed it with oil and it slid around the crank - with a little work. It's hard to explain but be sure you are pushing 'around' the crank... it'll go.

Marty

 

Yeah, it sounds easy, but it isn't. I am certain that I am pushing it around the crank. I have tried pushing on it very hard and it won't go. I tried pressing it up against the crank to compress the seal while also pushing it in, and it refuses to move. The hole is definitely clear, I slid a screw driver through the hole multiple times.

 

I don't understand, how can you push a straight screwdriver through the seal area when it's curved???

 

I ground the tip off of a long screw driver with about a 3/16" diameter shaft and tapped it through. It goes through and comes out the other side.

 

I just don't know what to say. This thing will not move. It goes in about a third of the way and stops. I have tried both seal halves. I am putting more force on this seal than alot of the toughest bolts I have had to loosen. I am even using needle nosed pliers grip it. Obviously, I don't care about the condition of the seal as long as something goes in there. I try pushing it just at the place that it goes into the block to be sure that I am pushing in a circular motion.
I slid a piece of frayed cable through the hole and out the other side and ran it back and forth, making sure it ran accross the block and the crank. I even rotated the crank. There just is no way that there is anything in the way. I held the seal half along the bottom of the crank and it is the right shape.
Go push on a brick wall, because that is exactly what this feels like. There is nothing in this world more frustrating.

 

Kind of a dumb question, but did you lube it with lots of oil first?

Did you try it from the opposite side? (another dumb one).

Weird, I've done a few, but not on FE's, and never had a problem, and from what I remember of putting together my 390 (twice), there should be no problem.

If you have a stick, one thing, with the main caps loose (not off, so as not to drop the crank half-out the motor) did you step on the clutch? This might let the tranny input shaft move enough to let the crank drop down a few more thousandths...

I'll have to go dig out my spare 390 block in the corner of the garage and see what she has in 'er ...

PS: Now you've done it, guys, now I'm starting to call them "her" - never humanized an inanimate object before...

 

I lubed it with oil well and tried it from both sides.
I also tried pressing on the clutch.

 

Sheesh...

 

Something just isn't right. There is a total lack of logic in this situation. I keep taking breaks, calming down, going back out and trying to ease it around making sure I press it up against the crank and push it "around." My fingers are all bruised and cut up. I so badly want to know why It won't go in. There is no way I am going to let this go. This has to be explained whether I have to tear the engine apart or not. The seal fits so perfectly into the cap, why won't it fit into the block????

How stupid would it be to have someone crank the engine (with the key) while I try to feed the seal around in the same direction of rotation?........That's what I thought.... REALLY stupid.

I know, I'll super glue it to the bottom of the crank, then I'll rotate it 180 and slap on the cap. What a great idea.

 

I thought of having someone turn the crank SLOWLY by hand, but ... ?

Is it possible that your pilot bearing (where the tranny input shaft fits into the back of the crank) and tranny is SO tight that it won't let the crank drop far enough ? I doubt it...

Is it possible that one of the pistons in the rear of the motor has the connecting rod at such a bad angle that it won't let the crank go? (dumb).

Would it be possible to unbolt the bell housing (from the tranny-to-bellhousing bolts), move the tranny back just enough to let the crank fall?

I know these new rubber seals are pretty stiff, but is it possible the one you got was sitting on the shelf for 10 years and got STIFF.... ???

 

I wouldn't know about the pilot bearing. How could I check that?

I can jiggle all of the connecting rods slightly, so I don't think they have a tight grip.

Do you think undoing the bellhousing bolts would work? I am not even sure if my bell housing is seperate from the tranny (three on the tree). I'll have to check.

Who'd have thought that I would spend more time on just the rear main than anything else. I probably could have had everything else done in 2 hours, but now I am going on two whole days. Plus, what I thought was going to be $50 tops in parts, turned out to be $115. Geez I was just trying to get by until I found a new engine. Talk about mistakes- had I ordered a new engine as soon as my pump failed I could have it in by now.

The seal I got was newly ordered just yesterday from napa. They get here fast because there is a warehouse (or maybe it's even the place they make these parts) near me. So I doubt it's old.

Here's a question, do you know how much steel there is supposed to be in the rear main seal? Perhaps if it there was too much steel (meaning the steel ring inside the rubber was too big), it wouldn't compress enough to go around. But then again, it looked awfully good sitting in the cap, and I was able to get it part way around the crank.

 

Well, I just undid my tranny to bellhousing bolts and seperated the two by at least a 1/2". I tried using a cherry picker on the back of the engine to lift up the engine and bellhousing to seperate it from the tranny and hopefully make the crank fall a bit, but the tranny came with, I wiggled it and tapped on it but it wouldn't come down even a slight bit. I gained no clearance by the crank at all. It didn't move a bit. This is so frustrating.

 

Sounds like you have to totally seperate the tranny from the engine - just enough to get the two dowels in the block out of the holes in the bellhousing - BE CAREFUL!